Safety-valve foe



UNITED sTATEs VPATENT oEEicE.

ZADOK H. MANN, OF CINCINNATI,

OHIO.

SAFETY-VALVE FOR STEAM-BOILERS.

Specification of Letters Patent No. 10,012, dated September 18, 1853.

To alt whom t may concern Be it known that I, ZADox H. MANN, of Cincinnati, Hamilton county, Ohio, have invented certain new and useful Improve-- ments in Safety-Valves for Steam-Boilers; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the annexed drawing, making part of this specification.

My invention has for its object an increase of sensibility of the safety-valve, so as to insure its opening at the' desired maximum of pressure, and also so as to increase the size of opening in proportion to the force of steam, and thus insure an adequate vent for the steam under all circumstances, and thereby remove all danger or possibility of explosion with a suitable boiler.

In the accompanying drawing my apparatus is represented by a side elevation. partly sectional.

() is a portion of a boiler.

(b) is a coupling nozzle bolted to the boiler. Into this nozzle is screwed the valve seat (c 0'). This seat is surmounted by a lip (e) curving upward, so as to present a cup-like rim. The valve (d CZ) is retained to its proper bearings by wings (d) and like its seat is surmounted by a cuplike rim (CW) a little within and concentric to that of the seat, so as to form between them an annular channel (e),through which the steam rushes at the slightest movement of the valve. The usual rod (f) by which the pressure of the weight (g) (or spring) is communicated to the valve becomes the spindle of a flutter wheel (it), against whose oblique vanes the steam impinging in its discharge from the channel (e) the said wheel is thereby rotated, and through the medium of the pinion (z') and spur-wheel gives rotation to the shaft (7c) of a governor (Z), whose sleeve (m) is connected to a lever This lever (n) is connected by a link (o) with the main lever (p), which carries the usual weight (g). This link is fixed to its desired position on the levers by a pin (g), a number of apertures being provided in the bar to allow of adjustment of the link. It is evident that the position of the link determines how much a given play of the balls shall lift the valve. A set-screw (s), also working in the link, gives facility for reducing as much as may be desired the stress of the weight at the first going off of the steam and starting of the valve. The lever (n) extends beyond its fulcrum and carries on the extended portion (nf) 'a counter weight (r) which is also adjustable in position and may be made so nearly to balance the balls of the governor as to make it respond to the slightest impulse on the iiutter wheel, and thus the sensibility of the action may be increased to any desired extent. The adjustability of the link therefore regulates the extent of the opening afforded and the adjustability of the counter-weight determines the sensibility of the valve, or in other words its promptitude of action with any degree of pressure above the maximum one determined by the position of the main weight. As a feature that affects to some extent the value of the governor action may be cited the fact that there is often an increase of friction as the valve lifts in the case of old safety valves where the pivots have worn somewhat flat. It may be worth while to observe that I have tried various devices for accomplishing this object, but have found nothing so effective as the combination of governor and supplementary lever.

I claim as my invention and desire to secure by Letters Patent- The construction `and application to a safety valve, of flutter wheel, governor and supplementary lever as described or equivalent devices, in order to insure promptness of action, and an increase of vent, according to the force of steam, and this I claim either with or without the adjustable link and counterweight as described.

In testimony whereof, I have hereunto set my hand before two subscribing witnesses.

Z. H. MANN.

IVitnesses:

GEO. H. KNIGHT, F. H. GETZENDANNER. 

